Combination straightener and tester for pipes



Dec. 14, 1943. B, BANNISTER 2,335,524

COMBINATION STRAIGHTENER AND TESTER FOR PIPES Filed Nov. 1, 1940 I z? ,2L 'fi 7 y m /z 14 1: 1 Fl E. 4. 20 J? [mm d022- Patented Dec. 14, 1943aaeaszi COMBINATION STRAIGHTENER AND- TESTER FOR PIPES Bryant Bannister,Mount Lebanon, 1%., assignor to National Tube Company,

New Jersey a corporation of Application November 1, 1940, Serial No.363,932

2.- Claims. This invention relates to the manufacture of pipes and tubesand more particularly to the axial straightening and hydraulic pressuretest-- ing thereof.

In the conventional manufacture of pipes and tubes they ar straightenedas they leave the cooling table, subsequent to which the ends arecropped and beveled or threaded as desired. The usual equipment forperforming the straightening. operation comprises ,a series of rolls setin opposed planes, or cross rolls with special profiles. Following thestraightening operation, the pipe or tube is transferred to a test pumpwhere it is filled with water and subjected to high pressure in order todetermine whether or not there is leakage. The foregoing operationsrequire a crew of workmen at the' straightening machine and another crewat the test pump. Usually. two test pumps spaced at substantialdistances are re-' quired to handle the product of one pipe mill.

From the foregoing, it will be seen that considerable conveying andhandling equipment is required to. straighten and test the pipe.

when a pipe or tube is su jected to tension,

there is an initial tendency for it to align itself with the directionof pull, provided, of course, the

tension is capable of stretching the material beyond its elastic limit.It is, accordingly, among the objects of the present invention to takeadvantage of this tendency while at the same time, or at least while inthe same apparatus, subjecting the interior of the workpiece to theapplication of a suitable test fluid. It will, of course, be understoodthat when pipes and tubes may be straightened and tested in the samemachine there will result a reduction in cost of labor and handling overthat required of conventional practice.

Another object is to accomplish the foregoing ends by the provision ofsimple and relativ ly inexpensive instrumentalities.

The foregoing and other apparent after referring to the drawing, inwhich:

Figure 1 is a fragmentary plan of an apparatus embodying the teachingsof the present invention; v

Figure 2 is an enlarged fragmentary plan of the left-hand portion ofFigure 1 referred to hereinbefore;

Figure 3 is a side elevation of the showingof Figure 2, certainof theparts thereof being shown in section;

Figure 4 is an enlarged fragmentary elevation of the means for sealingthe ends of thepipe to be straightened and tested:

objects will be more Figure 5 is a view on the line V-V of Figure 4;

I and,

Figure -6-is a sectional view on the line VI--VI of Figure 3.

Referring more particularly to the drawing, the numeral 2 generallydesignates a bed or base upon which there is received pipes or tubes tobe tested, the latter, referred to hereinafter at X, being conveyed overa suitable skidway or other conveying device 3 preferably disposed atthe discharge end of a cooling table (not shown).

Disposed at either end of the bed'or base 2 is a hydraulic cylinder 4each containing a suitable piston (not shown) and having the piston rod5 thereof extending inwardly and, therefore, in opposed relationship onewith respect to the other. Carried on the inner and therefore the mostadjacent ends of each-of the piston rods 5 is a clevis 6 to which thereis pivotally connected as at! the converging inner ends of apair oftoggle links 9, the latter carrying on their outer ends pivot pins l0which are connected to the rearward ends of a pair of pliers, the latterbeing pivotally interconnected intermediate their ends as shown at 12.The gripping, ends of the pliers ll, designated at l3, are transverselyconcaved and provided with serrated edges l4. Disposed between thegripping ends l3 of each of the pairs of pliers II is a cylindrical plugl8 which carries on its outer end an exterior-1y screw threadedcylindrical portion 20 of reduced diameter. Connected to thiscylindrical portion 20 is a coniform nozzle portion 22 having at thebase thereof an interiorly threaded cylindrical recess 24. Referringmore particularly to Figure 4 of the drawings, it will be perceived thatwhile the rearward portion of the base of the nozzle 22 abuts thecorrespondingly adjacent surface of the plug I8,

there is provided between the said nozzle and the said plug an annularrecess '26 which accommodates an annular, expansible tube 28 of suitablehigh strength resilient material. The plug I8 and nozzle 22 .arecentrally bored as shown at 30 and the expansible annular tube 28communicates therewith at diametrically opposite points, by way of beingprovided with tubes 32 which extend at least partially through radialpassageways 34 which are conjointly formed from the forward andrearwardportions of the plug I8 and nozzle 22, respectively. As shown mostclearly in Figure 3, the central bore 30 through the plug l8 and nozzle22 communicates adjacent the rear of the said plug with a rightangularly extending aperture 35 which communicates with a suitablesource of fluid under pressure (not shown). Ac-

- II and the conii'orm nozzle the overbalancing line when it is turnedon.

cordingto the foregoing construction and arrangement, it will be seenthat when fluid under pressure is applied to either one or'both of theright angular apertures 35 in the plugs d8, it will move through thecentral bore 30 in the plug 22, and completely flll the interior of thepipe or tube X to be tested. When the test fluid completely fills thepipe x some 01' the fluid will flow through the radial passageways 3!,tubes 32, and annular expansibie tubes 28, and cause the latter toexpand outwardly. Accordingly, the ends of the test piece are disposedover th nozzles 22 and plugs l8 and within the gripp ends l3 of thepliers ll. As clearly shown in Figure 3, the plug ll serves as aninternal support for the test piece, thus preventing the jaws l3 fromcausing it to collapse. As soon as fluid tight connections aremaintained at either end or the test piece x and the interior of thelatter supplied with test fluidunder the required pressure, fluid isadmitted tovthe ad- Jacent ends of the cylinders 4, the pistons of which(not shown) are madeto draw the piston rods I in opposite directions.The drawing apart of the piston rods is continued sufliciently tostretch the test piece x beyond its elastic limit,' whereby it isstraightened.

For supplying fluid under pressure through the apertures 35 at therearward ends 01' the plugs I, a one-way valve 31 is provided in the lowpressure line; and this is automatically closed by pressure of thehigher pressure In order to accommodate test pieces X which vary as tolength, one or both of the cylinders l is made adiustable inany-suitable manner (not shown) on the base or bed 2.

While I have shown and described a specific '1. Apparatus forstraightening and pressuretesting a metallic tubular article,comprising.

combinedgripping and sealing means for each of the ends of the metallictubular article, at least one or said means including a movabledrawhead, gripping means carried by said movable drawhead for engagingthe exterior of one end of said article, a sealing plug carried by saidgripping means and adapted to sealfihe adjacent end 01 said article,said plug serving as an internal support for said article while it isbeing gripped, means operating through said sealing plug to admit testfluid to the interior of said article, and "means for moving saiddrawhead relative to the other combined gripping and sealing meanssuiliciently to stretch said article beyond its elastic limit.

2. Apparatus for straightening and pressuretesting a metallic tubulararticle, comprising combined gripping and sealing means for each 01' theends of said article, each of said means including means for-grippingthe exterior of one end of said article, a plug adapted to seal theadjacent 0 end of said article and toserve as an internal support forsaid article while it is being gripped, means operating through one ofsaid plugs to admit test fluid to the interior of said article and meansfor moving said combined means relative to each other sufliciently tostretch said article beyond its elastic limit.

BRYANT nanms'ma.

